As per the normal bank rules, the Bank is always supposed to provide with a quick access pin for each customer whenever they issue a new customer ID. You didn't mention in your question, how did you receive this new customer ID, whether through the bank directly, through a printed mail sent by the bank, or through electronic media like email or phone.
But whichever is the case, it is evident that the bank will surely provide you with a quick access number for you new customer ID, which you can change afterwards. In no way, you can use the earlier pin number for the new user ID.
So, for this, you need to either contact your branch, or you can send an email enquiry to the internet banking customer care support. They will provide you with either an OTP to log in, or they can provide with a temporary password which you can change later.
Another thing is, if you have tried with a wrong password combination more than three times a day, your online banking will be blocked. In that case, you have to follow the same steps discussed above to get it unblocked. So I think that is the only way, this issue can be resolved.